US5686326A - Method of making thin film transistor - Google Patents

Method of making thin film transistor Download PDF

Info

Publication number
US5686326A
US5686326A US08/473,989 US47398995A US5686326A US 5686326 A US5686326 A US 5686326A US 47398995 A US47398995 A US 47398995A US 5686326 A US5686326 A US 5686326A
Authority
US
United States
Prior art keywords
electrode
layer
semiconductor layer
insulating layer
insulating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/473,989
Inventor
Nobuko Kitahara
Tetsuya Kaneko
Takashi Enomoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP60171141A external-priority patent/JPS6232651A/en
Priority claimed from JP15328086A external-priority patent/JPS639157A/en
Priority claimed from JP61153282A external-priority patent/JPH073872B2/en
Application filed by Canon Inc filed Critical Canon Inc
Priority to US08/473,989 priority Critical patent/US5686326A/en
Application granted granted Critical
Publication of US5686326A publication Critical patent/US5686326A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
    • H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body
    • H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
    • H01L27/124—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/66007—Multistep manufacturing processes
    • H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
    • H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
    • H01L29/66409—Unipolar field-effect transistors
    • H01L29/66477—Unipolar field-effect transistors with an insulated gate, i.e. MISFET
    • H01L29/66742—Thin film unipolar transistors
    • H01L29/6675—Amorphous silicon or polysilicon transistors
    • H01L29/66765—Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78606—Thin film transistors, i.e. transistors with a channel being at least partly a thin film with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device

Definitions

  • This invention relates to a thin film transistor (hereinafter called TFT) and a process for producing the same, particularly a TFT and a process for producing the same which are intended to improve the yield of TFT and simplify the production steps.
  • TFT thin film transistor
  • the TFT according to the present invention is applicable for, for example, switching transistors, etc. of an active type liquid crystal display device.
  • FIG. 1 shows a schematic sectional view of TFT of the prior art in an active type liquid crystal display device.
  • the TFT in this Figure is prepared as follows. First, on an insulating substrate 1 made of glass, etc., a gate electrode 2 and a picture element electrode 3 are formed, and an insulating layer 4 is formed on these electrodes. Subsequently, on the insulating layer 4 is deposited a semiconductor layer and the unnecessary portion is removed by selective etching to form a semiconductor layer 5 for generating channel. Subsequently, after formation of a contact hole 60 the main electrodes 7 and 8 (here, the source electrode 7 and the drain electrode 8) are formed.
  • At least 5 photolithographic steps are required for preparation of TFT of the prior art as described above. That is, they are the respective steps of forming a gate electrode 2, a picture element electrode 3, a semiconductor layer 5, a contact hole 6 and main electrodes 7 and 8. In carrying out these steps, high precision are required for alignment between the gate electrode 2 and the semiconductor layer 5 or between the semiconductor layer 5 and the main electrodes 7 and 8 as well as for dimensions thereof.
  • the insulating region such as the insulating layer 4 is susceptible to damages to form pinholes therein, whereby there has been also the problem that deterioration of the characteristics of TFT or leak at the crossed portion between the multi-layer wirings (hereinafter called cross-point) occurs to lower the yield.
  • the insulating layer 4 suffers from damages in the etching step for forming the semiconductor layer 5 on the insulating layer 4 and the etching step for forming the contact hole 6 on the insulating layer 4, whereby leak occurs between the gate electrode 2 and the source electrode 7 at higher probability to lower the yield of TFT.
  • An object of the present invention is to provide a novel TFT and a process for producing the same which overcome the problems of prior TFT as described above.
  • Another object of the present invention is to provide a process for producing a TFT which requires smaller number of steps and gives little alignment error as compared with the prior art.
  • a TFT comprising a gate electrode, an insulating layer and a semiconductor layer formed and laminated on an insulating substrate, said insulating layer and said semiconductor layer having the same planar pattern.
  • a process for producing a TFT comprising a gate electrode, an insulating layer and a semiconductor layer formed and laminated on an insulating substrate, which comprises forming said gate electrode on said insulating substrate, an insulating layer thereon and further a semiconductor layer thereon by lamination, and then subjecting said insulating layer and said semiconductor layer to patterning at the same time with the same pattern, thereby forming the insulating layer and the semiconductor layer of the thin film transistor.
  • control electrodes on an insulating substrate
  • FIG. 1 is a schematic sectional view of a TFT of the prior art in an active type liquid crystal display device
  • FIG. 2(A) is a schematic plan view of an embodiment of the TFT according to the present invention and FIG. 2(B) a sectional view taken along the line A-A' thereof;
  • FIGS. 3(A)-3(C) are schematic illustrations of the production steps showing an embodiment of the process for producing TFT according to the present invention.
  • FIGS. 4(A)-4(E) are schematic longitudinal sectional views of production steps showing another embodiment of the process for producing TFT according to the present invention.
  • FIGS. 5(A)-5(D) are schematic longitudinal sectional views of production steps when the process for producing TFT of the present invention is used for the process for producing an active type liquid crystal device;
  • FIGS. 6(A)-6(D) are schematic longitudinal sectional views of production steps when the process for producing TFT of the present invention is used for the process for producing a transfer device of photosensor in an image reading device such as facsimile, etc.;
  • FIGS. 7(A)-7(C) are schematic longitudinal sectional views of production steps showing still another embodiment of the process for producing TFT of the present invention.
  • FIGS. 8(A)-8(D) are schematic longitudinal sectional views of production steps showing another embodiment when the process for producing TFT of the present invention is used for a process for producing an active type liquid crystal display device;
  • FIGS. 9(A)-9(C) are schematic longitudinal sectional views of production steps showing still another embodiment when the process for producing TFT is used for a process for producing a transfer device of photosensor in an image reading device such as facsimile, etc.
  • FIG. 2(A) is a schematic plan view of an embodiment of the TFT according to the present invention and FIG. 2(B) a sectional view taken along the line A-A' thereof.
  • a gate electrode 12 on an insulating substrate 11 such as glass, etc., a gate electrode 12, a wiring 12' and a picture element electrode 13 (e.g. ITO, etc.) are formed, and on the gate electrode 12 is formed through an intermediary insulating layer a semiconductor layer 15 with the same planar pattern. And, on both ends of the semiconductor layer, the source electrode 16 and the drain electrode 17 are formed, with the source electrode being connected to the wiring 16' and the drain electrode 17 to the picture element electrode 13, respectively.
  • a gate electrode 12 on an insulating substrate 11 such as glass, etc.
  • a wiring 12' and a picture element electrode 13 e.g. ITO, etc.
  • the cross-points of the wiring 12' and the wiring 16' are separated from each other with the insulating layer 14' and the semiconductor layer 15' interposed therebetween, and the insulating layer 14' and the semiconductor layer 15' are formed by patterning at the same time as formation of the insulating layer 14 and the semiconductor layer of the TFT.
  • liquid crystal and further the common electrode such as ITO, etc. to form an active type liquid crystal device. Accordingly, by applying previously a driving voltage on the wiring 16' and applying an appropriate voltage through the wiring 12' on the gate electrode 12 to turn on the TFT of the present invention, driving voltage is applied on the picture element electrode 13, whereby the liquid crystal can be driven by the electric field between the picture element electrode and the common electrode.
  • this embodiment is simplified in structure as compared with the prior art example as shown in FIG. 1. Further, when a liquid crystal display device is costructed as described above, since there is no insulating layer on the picture element electrode, the voltage for driving the liquid crystal can be made smaller to alleviate the load on the driving circuit power source.
  • FIGS. 3(A)-3(C) are schematic illustrations of the production steps showing an embodiment of the process for producing TFT according to the present invention.
  • a gate electrode 12, a wiring 12' and a picture element electrode 13 are formed on an insulating substrate 11 on an insulating substrate 11 .
  • the picture element electrode 13 is formed of a material different from the electrode 12, etc. (for example, the gate electrode 12, etc. is made of polycrystalline silicon and the picture element 13 made of ITO), it is necessary to perform patterning in separate steps, respectively.
  • an insulating layer 20 such as SiO 2
  • a semiconductor layer 21 such as polycrystalline silicon, amorphous silicon, etc.
  • the insulating layer 20 and the semiconductor layer 21 are subjected to patterning with the same pattern to form an insulating layer 14 which becomes the gate insulating film of TFT and a semiconductor layer 15 which becomes the channel generating region of TFT.
  • the insulating layer 14 and the semiconductor layer 15 are subjected to patterning so as to be separated from the pattern of the picture element electrode 13.
  • an insulating layer 14' and a semiconductor layer 15' are formed on the portion which becomes the cross-point on the wiring 12'.
  • a metal or polycrystalline silicon for electrode is deposited and a source electrode 16, a wiring 16' and a drain electrode 17 are formed by patterning.
  • the drain electrode 17 is connected to the picture element electrode 13.
  • the semiconductor layer 15 is sufficiently larger than the width of the electrode 12 and also no step of providing a contact hole as practiced in the prior art is required, and therefore the process will receive influences of the positional discrepancy in patterns through alignment errors with difficulty. Therefore, TFT can be produced without requiring high precision, whereby the production steps can be simplified.
  • FIGS. 4(A)-4(E) are longitudinal sectional views of the production steps of another embodiment of the present invention.
  • a gate electrode 402 which is the control electrode.
  • a first insulating layer 403 such as of silicon nitride, silicon oxide, etc.
  • a semiconductor layer 404 such as of polycrystalline silicon, amorphous silicon, etc. is formed thereon, followed further by formation of a second insulating layer 408 such as of silicon nitride, silicon oxide, etc. for insulation and protection, continuously by lamination by means of a film forming device.
  • an opening portion for connecting a source electrode and drain electrode to the semiconductor layer 404 as described hereinafter is provided.
  • an impurity semiconductor layer 407 doped with, for example, an element such as phosphorus, etc. is formed which makes the semiconductor layer 404 ohmic contact with the source electrode and the drain electrode, and further an electroconductive layer for electrode is formed by deposition.
  • the electroconductive layer is etched to form a source electrode 405 and a drain electrode 406 which are the main electrodes. Further, with the source electrode 405 and the drain electrode 406 as the mask, unnecessary impurity semiconductor layer 407 is removed.
  • the first insulating layer 403, the semiconductor layer 404 and the second insulating layer 408 are subjected simultaneously to patterning with the same pattern to form a TFT.
  • the semiconductor layer and the second insulating layer are removed simultaneously with the same pattern after formation of the drain electrode, there occurs no such phenomenon of drop-off of the source electrode and the drain electrode from the stepped portion, even if positional discrepancy in patterns may occur between the source electrode, the drain electrode and the first insulating layer, the semiconductor layer and the second insulating layer.
  • highly precise pattern alignment can be reduced to simplify the production steps and also improve reliability of wiring, namely yield of TFT.
  • the surface of the portion corresponding to the channel of TFT is covered with the second insulating layer from the beginning of the step, it will not receive any influence of various damages, contamination, etc. in the course of the step, whereby there is the great advantage that constantly stable transistor characteristics can be obtained.
  • FIGS. 5(A)-5(D) are longitudinal sectional views of the production steps showing an embodiment when the TFT obtained according to the process of the present invention is used for an active type liquid crystal device.
  • a gate electrode 402 and a picture element electrode 409 are formed on an insulating substrate 401.
  • a first insulating layer 403, a semiconductor layer 404 and a second insulating layer 408 for insulation and protection are formed by lamination.
  • an opening portion for connecting a source electrode and a drain electrode to the semiconductor layer 403 and an opening portion for connecting a drain electrode to the picture element electrode 409 are provided.
  • an impurity semiconductor layer 407 and an electroconductive layer for electrode are deposited, and a source electrode 405 and a drain electrode 406 are formed by patterning the electroconductive layer similarly as in the step shown in FIG. 4(D) as described above, and further the unnecessary impurity semiconductor layer is removed.
  • an electrode wiring can be formed by similarly providing an opening portion.
  • This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment shown in FIG. 4. That is, as shown in FIG. 5(D), since substantially no insulating layer exists on the picture element electrode 409, the voltage for driving the liquid crystal can be made smaller, whereby the load on the driving circuit power source can be alleviated.
  • FIGS. 6(A)-6(D) are schematic longitudinal sectional views of production steps showing one embodiment when the process for producing TFT of the present invention is used for a transfer device of photosensor device in an image reading device such as facsimile, etc.
  • an insulating substrate 401 On an insulating substrate 401 are formed a gate electrode 402 of TFT and a lower layer electrode 410 of a capacitor for accumulation of image signals. Although not shown, electrodes for control may also be provided below the photosensor. Next, an insulating layer 403, a photoconductive semiconductor layer 404a and a second insulating layer 408 are formed by lamination.
  • an opening portion for connecting a source electrode and a drain electrode for TFT, an opening portion for connecting the upper electrode of the accumulating capacitor and an opening portion for connecting the upper electrode of the photosensor are provided on the photoconductive semiconductor 404a. It is also possible to use a constitution in which no opening portion for connecting the upper electrode of the accumulating capacitor is provided.
  • an impurity semiconductor layer and an electroconductive layer for electrode are deposited and, similarly as in the step shown in FIG. 4(D), as described above, by patterning of the electroconductive layer, a power supplying wire 411, sensor individual electrodes 412, an accumulating capacitor upper layer electrode 413, a source electrode 405 of TFT, a drain electrode 406 and a signal take-out wire 414 and wires for connecting the respective members are formed, and further the unnecessary impurity semiconductor layer is removed.
  • This embodiment has the following advantages as compared with the photosensor of the prior art.
  • the surface of the portion corresponding to the channel of TFT is covered with a protective layer from the beginning of the step, it will not receive the influences of various damages, contamination, etc. in the course of the steps, whereby there is the great advantage that constantly stable transistor characteristics and sensor characteristics can be obtained.
  • FIGS. 7(A)-7(C) are schematic longitudinal sectional views of production steps showing still another embodiment of the process for producing TFT of the present invention.
  • a gate electrode 702 which is the control electrode is formed on an insulating substrate 701.
  • an insulating layer 703 such as of silicon nitride, silicon oxide, etc. is formed, on which a semiconductor layer 704 such as of polycrystalline silicon, amorphous silicon, etc. is formed, followed further by formation of an impurity semiconductor layer 707 doped with an element such as phosphorus, etc. which takes ohmic contact with the source electrode and the drain electrode, successively by lamination.
  • an electroconductive layer for electrode is formed by deposition and by subjecting the electroconductive layer and the impurity semiconductor layer to patterning, the source electrode 705 and the drain electrode 706 which are main electrode are formed.
  • the insulating layer 703 and the semiconductor layer 704 are subjected to patterning at the same time with the same pattern to form a TFT.
  • the insulating layer and the semiconductor layer are removed with the same pattern after formation of the source electrode and the drain electrode, there occurs no phonemenon of drop-off of the source electrode and the drain electrode from the stepped portion, even if positional discrepancy in patterns may occur between the source electrode, the drain electrode and the insulating layer, the semiconductor layer whereby no highly precise pattern alignment is required to simplify the production steps and improve reliability of wiring, namely yield.
  • the etching step added for exposing a part of the gate electrode in the process for producing TFT of the prior art can be obviated to reduce the number of steps.
  • FIGS. 8(A)-8(D) are schematic longitudinal sectional views of preparation steps showing still another embodiment of the process for producing TFT of the present invention when used for production of an active type liquid crystal display device.
  • a gate electrode 702 and a picture element electrode 709 are formed on an insulating substrate 701.
  • an insulating layer 703, a semiconductor layer 704 and an impurity semiconductor layer 707 are formed by lamination.
  • an opening portion for connecting a drain electrode 706 to the picture element electrode 709 is provided.
  • a source electrode 705 and a drain electrode 706 are formed.
  • an opening portion can be provided to form an electrode wiring.
  • This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment as shown in FIG. 7. That is, while an insulating layer exists on the picture element electrode in the prior art, substantially no insulating layer exists on the picture element electrode 709 as shown in FIG. 8(D), and therefore the voltage for driving the liquid crystal can be made smaller to alleviate the load on the driving circuit power source.
  • FIGS. 9(A)-9(C) are schematic longitudinal sectional views of preparation steps showing still another embodiment of the process for producing TFT of the present invention when employed for production of a transfer device of photosensor in an image reading device such as facsimile, etc.
  • a gate electrode 702 of TFT and a lower layer electrode 710 of a capacitor for accumulation of image signals are formed on an insulating substrate 701.
  • an insulating layer 703, a photoconductive semiconductor layer 704a and an impurity semiconductor layer 707 are formed by lamination.
  • an electroconductive layer for electrode is deposited, and the electroconductive layer and the impurity semiconductor layer are subjected to patterning to form a power source supplying wire 711, sensor individual electrodes 712, an accumulating capacitor upper layer electrode 713, a source electrode 705 and a drain electrode 706 of TFT, a signal take-out wire 714 and wires for connecting respective members.
  • the insulating layer 703 and the photoconductive semiconductor layer 704a are subjected simultaneously to patterning with the same pattern to form a photosensor having a TFT for transfer.
  • This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment as shown in FIG. 8.
  • the stepped difference is formed because the photoconductive semiconductor layer is subjected to patterning.
  • the insulating layer 703 and the semiconductor layer 704a are left to remain beneath the wiring for connecting the photosensor, the capacitor for accumulation and TFT, there is substantially no stepped difference, whereby the wiring can be arranged smoothly and reliability of wiring is high, thus contributing advantageously to improvement of yield.
  • the insulating layer 703 and the semiconductor layer 704 receiving no influence of selective etching are left to remain as such beneath the capacitor for accumulation, the risk of lead between the upper and lower electrodes of the capacitor for accumulation can be markedly reduced, thus further contributing to improvement of yield of the whole device.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Liquid Crystal (AREA)
  • Thin Film Transistor (AREA)

Abstract

A thin film transistor comprises a gate electrode, an insulating layer and a semiconductor layer formed and laminated on an insulating substrate, said insulating layer and said semiconductor layer having the same planar pattern.

Description

This application is a division of application Ser. No. 08/167,117 filed Dec. 16, 1993 now abandoned which is a continuation of Ser. No. 07/855,484 filed Mar. 23, 1992, abandoned, which is a continuation of application Ser. No. 07/523,310 filed May 21, 1990, abandoned, which is a continuation of application Ser. No. 07/210,205 filed Jun. 20, 1988, abandoned, which is a continuation of application Ser. No. 06/892,087 filed Aug. 1, 1986, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a thin film transistor (hereinafter called TFT) and a process for producing the same, particularly a TFT and a process for producing the same which are intended to improve the yield of TFT and simplify the production steps.
The TFT according to the present invention is applicable for, for example, switching transistors, etc. of an active type liquid crystal display device.
2. Related Background Art
FIG. 1 shows a schematic sectional view of TFT of the prior art in an active type liquid crystal display device.
The TFT in this Figure is prepared as follows. First, on an insulating substrate 1 made of glass, etc., a gate electrode 2 and a picture element electrode 3 are formed, and an insulating layer 4 is formed on these electrodes. Subsequently, on the insulating layer 4 is deposited a semiconductor layer and the unnecessary portion is removed by selective etching to form a semiconductor layer 5 for generating channel. Subsequently, after formation of a contact hole 60 the main electrodes 7 and 8 (here, the source electrode 7 and the drain electrode 8) are formed.
When an appropriate voltage is applied on the gate electrode 2 of the TFT thus prepared, a channel is formed in the semiconductor layer 5, wherein TFT becomes the ON-state. Accordingly, if driving voltage is applied on the source electrode 7 of the TFT, driving voltage can be applied on the picture element electrode 3 through the TFT, whereby the liquid crystal (not shown) can be driven at any desired time.
As can be apparently seen from the above description, at least 5 photolithographic steps are required for preparation of TFT of the prior art as described above. That is, they are the respective steps of forming a gate electrode 2, a picture element electrode 3, a semiconductor layer 5, a contact hole 6 and main electrodes 7 and 8. In carrying out these steps, high precision are required for alignment between the gate electrode 2 and the semiconductor layer 5 or between the semiconductor layer 5 and the main electrodes 7 and 8 as well as for dimensions thereof.
However, according to the production process in the prior art, due to the alignment errors in the respective photolithographic steps, there has been the problem that discrepancy in position and dimension of the portions superposed of the photomask surfaces having patterns is liable to occur.
Further, due to a large number of etching steps, the insulating region such as the insulating layer 4 is susceptible to damages to form pinholes therein, whereby there has been also the problem that deterioration of the characteristics of TFT or leak at the crossed portion between the multi-layer wirings (hereinafter called cross-point) occurs to lower the yield. In the prior art example as described above, the insulating layer 4 suffers from damages in the etching step for forming the semiconductor layer 5 on the insulating layer 4 and the etching step for forming the contact hole 6 on the insulating layer 4, whereby leak occurs between the gate electrode 2 and the source electrode 7 at higher probability to lower the yield of TFT.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel TFT and a process for producing the same which overcome the problems of prior TFT as described above.
Another object of the present invention is to provide a process for producing a TFT which requires smaller number of steps and gives little alignment error as compared with the prior art.
According to one aspect of the present invention, there is provided a TFT comprising a gate electrode, an insulating layer and a semiconductor layer formed and laminated on an insulating substrate, said insulating layer and said semiconductor layer having the same planar pattern.
According to another aspect of the present invention, there is provided a process for producing a TFT comprising a gate electrode, an insulating layer and a semiconductor layer formed and laminated on an insulating substrate, which comprises forming said gate electrode on said insulating substrate, an insulating layer thereon and further a semiconductor layer thereon by lamination, and then subjecting said insulating layer and said semiconductor layer to patterning at the same time with the same pattern, thereby forming the insulating layer and the semiconductor layer of the thin film transistor.
According to still another aspect of the present invention, there is provided a process for producing a TFT comprising the steps of:
forming a control electrode on an insulating substrate;
laminating successively a first insulating layer, a semiconductor layer and a second insulating layer;
providing an opening portion at the second insulating layer and forming main electrodes through the opening portion; and
subjecting said first insulating layer, said semiconductor layer and said second insulating layer to patterning after formation of the main electrodes.
According to still another aspect of the present invention, there is provided a process for producing a TFT, comprising the steps of:
forming control electrodes on an insulating substrate;
further laminating successively an insulating layer and a semiconductor layer;
forming main electrodes on the semiconductor layer; and
subjecting said insulating layer and said semiconductor layer to patterning after formation of the main electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view of a TFT of the prior art in an active type liquid crystal display device;
FIG. 2(A) is a schematic plan view of an embodiment of the TFT according to the present invention and FIG. 2(B) a sectional view taken along the line A-A' thereof;
FIGS. 3(A)-3(C) are schematic illustrations of the production steps showing an embodiment of the process for producing TFT according to the present invention;
FIGS. 4(A)-4(E) are schematic longitudinal sectional views of production steps showing another embodiment of the process for producing TFT according to the present invention;
FIGS. 5(A)-5(D) are schematic longitudinal sectional views of production steps when the process for producing TFT of the present invention is used for the process for producing an active type liquid crystal device;
FIGS. 6(A)-6(D) are schematic longitudinal sectional views of production steps when the process for producing TFT of the present invention is used for the process for producing a transfer device of photosensor in an image reading device such as facsimile, etc.;
FIGS. 7(A)-7(C) are schematic longitudinal sectional views of production steps showing still another embodiment of the process for producing TFT of the present invention;
FIGS. 8(A)-8(D) are schematic longitudinal sectional views of production steps showing another embodiment when the process for producing TFT of the present invention is used for a process for producing an active type liquid crystal display device; and
FIGS. 9(A)-9(C) are schematic longitudinal sectional views of production steps showing still another embodiment when the process for producing TFT is used for a process for producing a transfer device of photosensor in an image reading device such as facsimile, etc.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following, the embodiments of the present invention are to be explained in detail by referring to the drawings.
FIG. 2(A) is a schematic plan view of an embodiment of the TFT according to the present invention and FIG. 2(B) a sectional view taken along the line A-A' thereof.
In the both Figures, on an insulating substrate 11 such as glass, etc., a gate electrode 12, a wiring 12' and a picture element electrode 13 (e.g. ITO, etc.) are formed, and on the gate electrode 12 is formed through an intermediary insulating layer a semiconductor layer 15 with the same planar pattern. And, on both ends of the semiconductor layer, the source electrode 16 and the drain electrode 17 are formed, with the source electrode being connected to the wiring 16' and the drain electrode 17 to the picture element electrode 13, respectively.
Although not clearly shown, the cross-points of the wiring 12' and the wiring 16' are separated from each other with the insulating layer 14' and the semiconductor layer 15' interposed therebetween, and the insulating layer 14' and the semiconductor layer 15' are formed by patterning at the same time as formation of the insulating layer 14 and the semiconductor layer of the TFT.
Further, in this embodiment, although not shown in FIGS. 2(A) and 2(B), on the picture element electrode 13 is formed liquid crystal and further the common electrode such as ITO, etc. to form an active type liquid crystal device. Accordingly, by applying previously a driving voltage on the wiring 16' and applying an appropriate voltage through the wiring 12' on the gate electrode 12 to turn on the TFT of the present invention, driving voltage is applied on the picture element electrode 13, whereby the liquid crystal can be driven by the electric field between the picture element electrode and the common electrode.
Thus, this embodiment is simplified in structure as compared with the prior art example as shown in FIG. 1. Further, when a liquid crystal display device is costructed as described above, since there is no insulating layer on the picture element electrode, the voltage for driving the liquid crystal can be made smaller to alleviate the load on the driving circuit power source.
Next, the process for producing TFT according to the present invention is to be explained.
FIGS. 3(A)-3(C) are schematic illustrations of the production steps showing an embodiment of the process for producing TFT according to the present invention.
First, as shown in FIG. 3(A), on an insulating substrate 11 are formed a gate electrode 12, a wiring 12' and a picture element electrode 13. However, when the picture element electrode 13 is formed of a material different from the electrode 12, etc. (for example, the gate electrode 12, etc. is made of polycrystalline silicon and the picture element 13 made of ITO), it is necessary to perform patterning in separate steps, respectively. Subsequently, an insulating layer 20 such as SiO2, and further a semiconductor layer 21 such as polycrystalline silicon, amorphous silicon, etc. are formed by lamination.
Next, as shown in FIG. 3(B), the insulating layer 20 and the semiconductor layer 21 are subjected to patterning with the same pattern to form an insulating layer 14 which becomes the gate insulating film of TFT and a semiconductor layer 15 which becomes the channel generating region of TFT. During this operation, the insulating layer 14 and the semiconductor layer 15 are subjected to patterning so as to be separated from the pattern of the picture element electrode 13. Also, although not shown in the drawing, simultaneously with patterning, an insulating layer 14' and a semiconductor layer 15' are formed on the portion which becomes the cross-point on the wiring 12'.
As the next step, as shown in FIG. 3(C), a metal or polycrystalline silicon for electrode is deposited and a source electrode 16, a wiring 16' and a drain electrode 17 are formed by patterning. The drain electrode 17 is connected to the picture element electrode 13.
In this embodiment, the semiconductor layer 15 is sufficiently larger than the width of the electrode 12 and also no step of providing a contact hole as practiced in the prior art is required, and therefore the process will receive influences of the positional discrepancy in patterns through alignment errors with difficulty. Therefore, TFT can be produced without requiring high precision, whereby the production steps can be simplified.
Also, while no selective etching step of the semiconductor layer 15 and no etching step for formation of a contact hole are required in this embodiment, even if such etching may be effected, no damage will be received at all, because the insulating layers 14 and 14' are protected with the semiconductor layers 15 and 15'. Accordingly, there is little possibility of occurence of leak, etc. between source and drain, whereby production yield of TFT can be improved markedly.
Having explained this embodiment by referring to the case when employed for an active type liquid crystal display device, this is of course not limitative of the present invention, but the present invention is widely applicable as active devices as a matter of course.
FIGS. 4(A)-4(E) are longitudinal sectional views of the production steps of another embodiment of the present invention.
First, as shown in FIG. 4(A), on an insulating substrate 401 is formed a gate electrode 402 which is the control electrode. On the gate electrode 402 and the insulating substrate 401 is formed a first insulating layer 403 such as of silicon nitride, silicon oxide, etc., and a semiconductor layer 404 such as of polycrystalline silicon, amorphous silicon, etc. is formed thereon, followed further by formation of a second insulating layer 408 such as of silicon nitride, silicon oxide, etc. for insulation and protection, continuously by lamination by means of a film forming device.
Next, as shown in FIG. 4(B), an opening portion for connecting a source electrode and drain electrode to the semiconductor layer 404 as described hereinafter is provided.
Next, as shown in FIG. 4(C), an impurity semiconductor layer 407 doped with, for example, an element such as phosphorus, etc. is formed which makes the semiconductor layer 404 ohmic contact with the source electrode and the drain electrode, and further an electroconductive layer for electrode is formed by deposition.
Next, as shown in FIG. 4(D), the electroconductive layer is etched to form a source electrode 405 and a drain electrode 406 which are the main electrodes. Further, with the source electrode 405 and the drain electrode 406 as the mask, unnecessary impurity semiconductor layer 407 is removed.
Next, as shown in FIG. 4(E), the first insulating layer 403, the semiconductor layer 404 and the second insulating layer 408 are subjected simultaneously to patterning with the same pattern to form a TFT.
In this embodiment, since no selective etching of semiconductor layer and insulating layer as practiced in the prior art is required, there is no instability accompanying selective etching to afford stable production steps.
Further, since the first insulating layer, the semiconductor layer and the second insulating layer are removed simultaneously with the same pattern after formation of the drain electrode, there occurs no such phenomenon of drop-off of the source electrode and the drain electrode from the stepped portion, even if positional discrepancy in patterns may occur between the source electrode, the drain electrode and the first insulating layer, the semiconductor layer and the second insulating layer. Thus, highly precise pattern alignment can be reduced to simplify the production steps and also improve reliability of wiring, namely yield of TFT. Also, in this embodiment, since the surface of the portion corresponding to the channel of TFT is covered with the second insulating layer from the beginning of the step, it will not receive any influence of various damages, contamination, etc. in the course of the step, whereby there is the great advantage that constantly stable transistor characteristics can be obtained.
FIGS. 5(A)-5(D) are longitudinal sectional views of the production steps showing an embodiment when the TFT obtained according to the process of the present invention is used for an active type liquid crystal device.
First, as shown in FIG. 5(A), on an insulating substrate 401 are formed a gate electrode 402 and a picture element electrode 409. Then, a first insulating layer 403, a semiconductor layer 404 and a second insulating layer 408 for insulation and protection are formed by lamination.
Next, as shown in FIG. 5(B), an opening portion for connecting a source electrode and a drain electrode to the semiconductor layer 403 and an opening portion for connecting a drain electrode to the picture element electrode 409 are provided.
Next, as shown in FIG. 5(C), an impurity semiconductor layer 407 and an electroconductive layer for electrode are deposited, and a source electrode 405 and a drain electrode 406 are formed by patterning the electroconductive layer similarly as in the step shown in FIG. 4(D) as described above, and further the unnecessary impurity semiconductor layer is removed. In the case of having a matrix wiring at the driving circuit portion of the liquid crystal display device, an electrode wiring can be formed by similarly providing an opening portion.
The order of the step of providing opening portions and the step of depositing an impurity semiconductor as shown above in FIG. 5(B) and 5(C) can be reversed, whereby it is also possible to obtain a constitution in which no impurity semiconductor remains at the connecting portion between the picture element electrode and the drain electrode.
Next, as shown in FIG. 5(D), by subjecting the first insulating layer 403, the semiconductor layer 404 and the second insulating layer 408 to patterning with the same pattern, a TFT applied for an active type liquid crystal display device is formed.
This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment shown in FIG. 4. That is, as shown in FIG. 5(D), since substantially no insulating layer exists on the picture element electrode 409, the voltage for driving the liquid crystal can be made smaller, whereby the load on the driving circuit power source can be alleviated.
FIGS. 6(A)-6(D) are schematic longitudinal sectional views of production steps showing one embodiment when the process for producing TFT of the present invention is used for a transfer device of photosensor device in an image reading device such as facsimile, etc.
First, as shown in FIG. 6(A), on an insulating substrate 401 are formed a gate electrode 402 of TFT and a lower layer electrode 410 of a capacitor for accumulation of image signals. Although not shown, electrodes for control may also be provided below the photosensor. Next, an insulating layer 403, a photoconductive semiconductor layer 404a and a second insulating layer 408 are formed by lamination.
Next, as shown in FIG. 6(B), an opening portion for connecting a source electrode and a drain electrode for TFT, an opening portion for connecting the upper electrode of the accumulating capacitor and an opening portion for connecting the upper electrode of the photosensor are provided on the photoconductive semiconductor 404a. It is also possible to use a constitution in which no opening portion for connecting the upper electrode of the accumulating capacitor is provided.
Next, as shown in FIG. 6(C), an impurity semiconductor layer and an electroconductive layer for electrode are deposited and, similarly as in the step shown in FIG. 4(D), as described above, by patterning of the electroconductive layer, a power supplying wire 411, sensor individual electrodes 412, an accumulating capacitor upper layer electrode 413, a source electrode 405 of TFT, a drain electrode 406 and a signal take-out wire 414 and wires for connecting the respective members are formed, and further the unnecessary impurity semiconductor layer is removed.
Next, as shown in FIG. 6(D), by subjecting simultaneously the first insulating layer 403, the photoconductive semiconductor layer 404a and the second insulating layer 408 to patterning with the same pattern, a photosensor having TFT for transfer can be formed.
This embodiment has the following advantages as compared with the photosensor of the prior art.
That is, similarly as the embodiment shown in FIG. 4, no selective etching of the semiconductor layer and the insulating layer is required, whereby there is no instability accompanying selective etching to afford stable production steps. Further, since the first insulating layer, the semiconductor layer and the second insulating layer are removed simultaneously with the same pattern after formation of the source electrode and the drain electrode, there occurs no phenomenon of drop-off of the source electrode and the drain electrode from the stepped portion, even if positional discrepancy in patterns may occur between the source electrode, the drain electrode and the first insulating layer, the semiconductor layer, the second insulating layer, whereby no highly precise pattern alignment is required to simplify the production steps and improve reliability of wiring, namely yield.
Also, since the surface of the portion corresponding to the channel of TFT is covered with a protective layer from the beginning of the step, it will not receive the influences of various damages, contamination, etc. in the course of the steps, whereby there is the great advantage that constantly stable transistor characteristics and sensor characteristics can be obtained.
FIGS. 7(A)-7(C) are schematic longitudinal sectional views of production steps showing still another embodiment of the process for producing TFT of the present invention.
First, as shown in FIG. 7(A), a gate electrode 702 which is the control electrode is formed on an insulating substrate 701. On the gate electrode 702 and the insulating substrate 701, an insulating layer 703 such as of silicon nitride, silicon oxide, etc. is formed, on which a semiconductor layer 704 such as of polycrystalline silicon, amorphous silicon, etc. is formed, followed further by formation of an impurity semiconductor layer 707 doped with an element such as phosphorus, etc. which takes ohmic contact with the source electrode and the drain electrode, successively by lamination.
Next, as shown in FIG. 7(B), an electroconductive layer for electrode is formed by deposition and by subjecting the electroconductive layer and the impurity semiconductor layer to patterning, the source electrode 705 and the drain electrode 706 which are main electrode are formed.
Next, as shown in FIG. 7(C), the insulating layer 703 and the semiconductor layer 704 are subjected to patterning at the same time with the same pattern to form a TFT.
In this embodiment, since no selective etching of the semiconductor layer and the insulating layer as practiced in the prior art example is required, there is no instability accompanying selective etching to afford stable production steps.
Further, since the insulating layer and the semiconductor layer are removed with the same pattern after formation of the source electrode and the drain electrode, there occurs no phonemenon of drop-off of the source electrode and the drain electrode from the stepped portion, even if positional discrepancy in patterns may occur between the source electrode, the drain electrode and the insulating layer, the semiconductor layer whereby no highly precise pattern alignment is required to simplify the production steps and improve reliability of wiring, namely yield.
Also, since the above step of removing simultaneously the insulating layer and the semiconductor layer also functions as the step of exposing a part of the gate electrode, the etching step added for exposing a part of the gate electrode in the process for producing TFT of the prior art can be obviated to reduce the number of steps.
FIGS. 8(A)-8(D) are schematic longitudinal sectional views of preparation steps showing still another embodiment of the process for producing TFT of the present invention when used for production of an active type liquid crystal display device.
First, as shown in FIG. 8(A), a gate electrode 702 and a picture element electrode 709 are formed on an insulating substrate 701. Next, an insulating layer 703, a semiconductor layer 704 and an impurity semiconductor layer 707 are formed by lamination.
Next, as shown in FIG. 8(B), an opening portion for connecting a drain electrode 706 to the picture element electrode 709 is provided.
Next, as shown in FIG. 8(C), a source electrode 705 and a drain electrode 706 are formed. In the case of a constitution having a matrix wiring at the driving circuit portion of the liquid crystal display device, also an opening portion can be provided to form an electrode wiring.
Next, as shown in FIG. 8(D), by subjecting simultaneously the insulating layer 703 and the semiconductor layer 704 to patterning with the same pattern, a TFT applied for an active type liquid crystal display device is formed.
This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment as shown in FIG. 7. That is, while an insulating layer exists on the picture element electrode in the prior art, substantially no insulating layer exists on the picture element electrode 709 as shown in FIG. 8(D), and therefore the voltage for driving the liquid crystal can be made smaller to alleviate the load on the driving circuit power source.
FIGS. 9(A)-9(C) are schematic longitudinal sectional views of preparation steps showing still another embodiment of the process for producing TFT of the present invention when employed for production of a transfer device of photosensor in an image reading device such as facsimile, etc.
First, as shown in FIG. 9(A), a gate electrode 702 of TFT and a lower layer electrode 710 of a capacitor for accumulation of image signals are formed on an insulating substrate 701. Although not shown, it is also possible to provide electrodes for control below the photosensor. Next, an insulating layer 703, a photoconductive semiconductor layer 704a and an impurity semiconductor layer 707 are formed by lamination.
Next, as shown in FIG. 9(B), an electroconductive layer for electrode is deposited, and the electroconductive layer and the impurity semiconductor layer are subjected to patterning to form a power source supplying wire 711, sensor individual electrodes 712, an accumulating capacitor upper layer electrode 713, a source electrode 705 and a drain electrode 706 of TFT, a signal take-out wire 714 and wires for connecting respective members.
Next, as shown in FIG. 9(C), the insulating layer 703 and the photoconductive semiconductor layer 704a are subjected simultaneously to patterning with the same pattern to form a photosensor having a TFT for transfer.
This embodiment has the following advantage in addition to the advantages as mentioned in the embodiment as shown in FIG. 8.
In the prior art, the stepped difference is formed because the photoconductive semiconductor layer is subjected to patterning. In the present invention, as shown in FIG. 9(C), since the insulating layer 703 and the semiconductor layer 704a are left to remain beneath the wiring for connecting the photosensor, the capacitor for accumulation and TFT, there is substantially no stepped difference, whereby the wiring can be arranged smoothly and reliability of wiring is high, thus contributing advantageously to improvement of yield.
Also, since the insulating layer 703 and the semiconductor layer 704 receiving no influence of selective etching are left to remain as such beneath the capacitor for accumulation, the risk of lead between the upper and lower electrodes of the capacitor for accumulation can be markedly reduced, thus further contributing to improvement of yield of the whole device.

Claims (16)

What we claim is:
1. A process for producing semiconductor device which comprises at least a thin film transistor comprising a gate electrode, an insulating layer, a semiconductor layer, an ohmic contact layer, and source and drain electrodes stacked on an insulating substrate, and at least a portion capable of accumulating charge comprising a first electrode, the insulating layer, the semiconductor layer, the ohmic contact layer and a second electrode stacked on the insulating substrate, which comprises the steps of:
forming the gate electrode and the first electrode on the insulating substrate;
stacking the insulating layer, the semiconductor layer and the ohmic contact layer in this order on the insulating substrate having the gate electrode and the first electrode thereon;
providing a layer of an electroconductive material for forming the source and the drain electrodes and the second electrode on the ohmic contact layer and patterning the layer to form the source and the drain electrodes and the second electrode; and
patterning the semiconductor layer and the insulating layer after formation of the source and the drain electrodes and the second electrode.
2. A process for producing a semiconductor device which comprises a thin film transistor comprising an insulating substrate, a controlling electrode formed on the insulating substrate, an insulating layer formed on the controlling electrode, a semiconductor layer formed on the insulating layer and source and drain electrodes electrically connected to the semiconductor layer; and a capacitor comprising a first electrode formed on the insulating substrate and a second electrode formed on the first electrode via an insulating layer and opposed to the first electrode, the source or the drain electrode of the thin film transistor being electrically connected to the second electrode, which comprises the steps of:
forming the controlling electrode and the first electrode on the insulating substrate;
laminating the insulating layer and the semiconductor layer in this order on the controlling electrode and the first electrode;
forming the source and the drain electrodes and the second electrode on the semiconductor layer; and
patterning the insulating layer and the semiconductor layer after formation of the source and the drain electrodes and the second electrode.
3. A process for producing a semiconductor device comprising a thin film transistor and a capacitor, comprising the steps of:
forming a controlling electrode of the thin film transistor and a first electrode of the capacitor on an insulating substrate;
forming a first insulating layer, a semiconductor layer and a second insulating layer in this order on the controlling electrode and the first electrode;
providing an opening portion in the second insulating layer and forming source and drain electrodes of the transistor and a second electrode of the capacitor on the semiconductor layer via the opening portion; and
patterning the first insulating layer, the semiconductor layer and said second insulating layer after formation of the the source and drain electrodes and the second electrode.
4. The process according to claim 2, wherein the source and the drain electrodes are provided on the semiconductor layer via an ohmic contact layer.
5. The process according to claim 4, further comprising a step of forming the ohmic contact layer on the semiconductor layer.
6. The process according to claim 3, wherein the source and the drain electrodes are provided on the semiconductor layer via an ohmic contact layer.
7. The process according to claim 6, further comprising a step of forming the ohmic contact layer on the semiconductor layer.
8. The process according to claim 1, wherein the portion capable of accumulating charge comprises a capacitor.
9. The process according to claim 1, wherein the at least a thin film transistor and the at least a portion capable of accumulating charge comprise plural thin film transistors and plural portions capable of accumulating charge.
10. The process according to claim 1, wherein the thin film transistor and the at least a portion capable of accumulating charge are in a matrix.
11. The process according to claim 1, wherein the semiconductor layer comprises polysilicon or amorphous silicon.
12. The process according to claim 1, wherein the ohmic contact layer comprises a doped semiconductor.
13. The process according to claim 2, wherein the semiconductor layer comprises polysilicon or amorphous silicon.
14. The process according to claim 4, wherein the ohmic contact layer comprises a doped semiconductor.
15. The process according to claim 3, wherein the semiconductor layer comprises polysilicon or amorphous silicon.
16. The process according to claim 6, wherein the ohmic contact layer comprises a doped semiconductor.
US08/473,989 1985-08-05 1995-06-07 Method of making thin film transistor Expired - Lifetime US5686326A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08/473,989 US5686326A (en) 1985-08-05 1995-06-07 Method of making thin film transistor

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
JP60171141A JPS6232651A (en) 1985-08-05 1985-08-05 Thin film transistor and manufacture thereof
JP60-171141 1985-08-05
JP61-153280 1986-06-30
JP15328086A JPS639157A (en) 1986-06-30 1986-06-30 Manufacture of thin film transistor
JP61-153282 1986-06-30
JP61153282A JPH073872B2 (en) 1986-06-30 1986-06-30 Method of manufacturing semiconductor device using thin film transistor
US89208786A 1986-08-01 1986-08-01
US21020588A 1988-06-20 1988-06-20
US52331090A 1990-05-21 1990-05-21
US85548492A 1992-03-23 1992-03-23
US16711793A 1993-12-16 1993-12-16
US08/473,989 US5686326A (en) 1985-08-05 1995-06-07 Method of making thin film transistor

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US16711793A Division 1985-08-05 1993-12-16

Publications (1)

Publication Number Publication Date
US5686326A true US5686326A (en) 1997-11-11

Family

ID=46250582

Family Applications (2)

Application Number Title Priority Date Filing Date
US08/473,989 Expired - Lifetime US5686326A (en) 1985-08-05 1995-06-07 Method of making thin film transistor
US08/476,283 Expired - Lifetime US5648663A (en) 1985-08-05 1995-06-07 Semiconductor structure having transistor and other elements on a common substrate and process for producing the same

Family Applications After (1)

Application Number Title Priority Date Filing Date
US08/476,283 Expired - Lifetime US5648663A (en) 1985-08-05 1995-06-07 Semiconductor structure having transistor and other elements on a common substrate and process for producing the same

Country Status (1)

Country Link
US (2) US5686326A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5942310A (en) * 1995-09-12 1999-08-24 Lg Electronics Inc. Liquid crystal display with increased aperture ratio
US6140162A (en) * 1998-06-19 2000-10-31 Lg Electronics Inc. Reduction of masking and doping steps in a method of fabricating a liquid crystal display
US6218206B1 (en) * 1998-03-31 2001-04-17 Mitsubishi Denki Kabushiki Kaisha Method for producing thin film transistor and thin film transistor using the same
US6232158B1 (en) * 1998-07-30 2001-05-15 Lg Philips Co., Lcd Thin film transistor and a fabricating method thereof
US6287899B1 (en) * 1998-12-31 2001-09-11 Samsung Electronics Co., Ltd. Thin film transistor array panels for a liquid crystal display and a method for manufacturing the same
US6365469B2 (en) * 1998-08-26 2002-04-02 Agere Systems Guardian Corp. Method for forming dual-polysilicon structures using a built-in stop layer
US20020149710A1 (en) * 2001-04-13 2002-10-17 Keum-Nam Kim Flat panel display device and method of manufacturing the same

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5374572A (en) * 1993-07-22 1994-12-20 Motorola, Inc. Method of forming a transistor having an offset channel section
KR100192370B1 (en) * 1996-01-10 1999-06-15 구자홍 Fabrication method of lcd device
JPH10142633A (en) * 1996-11-15 1998-05-29 Mitsubishi Electric Corp Thin film transistor integrated device, manufacture thereof, and liquid crystal display device
TWI326790B (en) * 2005-02-16 2010-07-01 Au Optronics Corp Method of fabricating a thin film transistor of a thin film transistor liquid crystal display and method of fabricating a transistor liquid crystal display
CN100452325C (en) * 2005-03-22 2009-01-14 友达光电股份有限公司 Production of thin-film transistor and liquid-crystal display devcie
JP5111745B2 (en) * 2005-08-24 2013-01-09 イビデン株式会社 Capacitor and manufacturing method thereof
EP2312280A1 (en) * 2009-10-07 2011-04-20 Dresser Wayne AB Fluid meter
US9373711B2 (en) 2013-02-27 2016-06-21 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device

Citations (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2044994A (en) * 1979-03-22 1980-10-22 Philips Electronic Associated Thin film transistors
JPS56164578A (en) * 1980-05-21 1981-12-17 Oki Electric Ind Co Ltd Manufacture of mos type semiconductor device
JPS58147069A (en) * 1982-02-25 1983-09-01 Sharp Corp Thin film transistor
EP0090661A2 (en) * 1982-03-31 1983-10-05 Fujitsu Limited A thin film field-effect transistor and a process for producing the same
US4425572A (en) * 1980-05-16 1984-01-10 Sharp Kabushiki Kaisha Thin film transistor
US4459739A (en) * 1981-05-26 1984-07-17 Northern Telecom Limited Thin film transistors
JPS59165088A (en) * 1983-03-11 1984-09-18 株式会社リコー Matrix array for thin film transistor
JPS609167A (en) * 1983-06-28 1985-01-18 Matsushita Electric Ind Co Ltd Semiconductor device and manufacture thereof
JPS6066864A (en) * 1983-09-22 1985-04-17 Seiko Instr & Electronics Ltd Mis type thin film transistor
JPS6098680A (en) * 1983-11-04 1985-06-01 Seiko Instr & Electronics Ltd Field effect type thin film transistor
JPS60160171A (en) * 1984-01-31 1985-08-21 Seiko Instr & Electronics Ltd Thin film transistor
JPS60160170A (en) * 1984-01-31 1985-08-21 Seiko Instr & Electronics Ltd Thin film transistor
JPS60211982A (en) * 1984-04-06 1985-10-24 Hitachi Ltd Thin film transistor
JPS60251266A (en) * 1984-05-29 1985-12-11 Toyota Motor Corp Cementation treatment using fluid particle and apparatus used directly for performing said treatment
JPS6151972A (en) * 1984-08-22 1986-03-14 Matsushita Electric Ind Co Ltd Thin film transistor array and manufacture thereof
US4582395A (en) * 1980-07-31 1986-04-15 Kabushiki Kaisha Suwa Seikosha Active matrix assembly for a liquid crystal display device including an insulated-gate-transistor
JPS6175379A (en) * 1984-09-21 1986-04-17 富士通株式会社 Manufacture of active matrix circuit
JPS6190193A (en) * 1984-10-09 1986-05-08 セイコーインスツルメンツ株式会社 Active matrix liquid crystal display unit
JPS6193488A (en) * 1984-10-12 1986-05-12 富士通株式会社 Silicon thin film transistor matrix and manufacture thereof
US4609930A (en) * 1983-05-06 1986-09-02 Seiko Instruments & Electronics Ltd. Thin film transistor
US4646424A (en) * 1985-08-02 1987-03-03 General Electric Company Deposition and hardening of titanium gate electrode material for use in inverted thin film field effect transistors
JPS62131578A (en) * 1985-12-03 1987-06-13 Seiko Instr & Electronics Ltd Manufacture of thin film transistor
US4684435A (en) * 1985-02-13 1987-08-04 Sharp Kabushiki Kaisha Method of manufacturing thin film transistor
US4958205A (en) * 1985-03-29 1990-09-18 Matsushita Electric Industrial Co., Ltd. Thin film transistor array and method of manufacturing the same
US4963955A (en) * 1985-04-11 1990-10-16 Canon Kabushiki Kaisha Photoelectric conversion apparatus
US5188974A (en) * 1987-10-31 1993-02-23 Canon Kabushiki Kaisha Method of manufacturing semiconductor device
US5462887A (en) * 1993-11-22 1995-10-31 Ernst Luder Process for making a matrix of thin layer transistors with memory capacitors

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60251667A (en) * 1984-05-28 1985-12-12 Seiko Epson Corp Thin-film transistor

Patent Citations (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2044994A (en) * 1979-03-22 1980-10-22 Philips Electronic Associated Thin film transistors
US4425572A (en) * 1980-05-16 1984-01-10 Sharp Kabushiki Kaisha Thin film transistor
JPS56164578A (en) * 1980-05-21 1981-12-17 Oki Electric Ind Co Ltd Manufacture of mos type semiconductor device
US4582395A (en) * 1980-07-31 1986-04-15 Kabushiki Kaisha Suwa Seikosha Active matrix assembly for a liquid crystal display device including an insulated-gate-transistor
US4459739A (en) * 1981-05-26 1984-07-17 Northern Telecom Limited Thin film transistors
JPS58147069A (en) * 1982-02-25 1983-09-01 Sharp Corp Thin film transistor
EP0090661A2 (en) * 1982-03-31 1983-10-05 Fujitsu Limited A thin film field-effect transistor and a process for producing the same
JPS59165088A (en) * 1983-03-11 1984-09-18 株式会社リコー Matrix array for thin film transistor
US4609930A (en) * 1983-05-06 1986-09-02 Seiko Instruments & Electronics Ltd. Thin film transistor
JPS609167A (en) * 1983-06-28 1985-01-18 Matsushita Electric Ind Co Ltd Semiconductor device and manufacture thereof
JPS6066864A (en) * 1983-09-22 1985-04-17 Seiko Instr & Electronics Ltd Mis type thin film transistor
JPS6098680A (en) * 1983-11-04 1985-06-01 Seiko Instr & Electronics Ltd Field effect type thin film transistor
JPS60160171A (en) * 1984-01-31 1985-08-21 Seiko Instr & Electronics Ltd Thin film transistor
JPS60160170A (en) * 1984-01-31 1985-08-21 Seiko Instr & Electronics Ltd Thin film transistor
JPS60211982A (en) * 1984-04-06 1985-10-24 Hitachi Ltd Thin film transistor
JPS60251266A (en) * 1984-05-29 1985-12-11 Toyota Motor Corp Cementation treatment using fluid particle and apparatus used directly for performing said treatment
JPS6151972A (en) * 1984-08-22 1986-03-14 Matsushita Electric Ind Co Ltd Thin film transistor array and manufacture thereof
JPS6175379A (en) * 1984-09-21 1986-04-17 富士通株式会社 Manufacture of active matrix circuit
JPS6190193A (en) * 1984-10-09 1986-05-08 セイコーインスツルメンツ株式会社 Active matrix liquid crystal display unit
JPS6193488A (en) * 1984-10-12 1986-05-12 富士通株式会社 Silicon thin film transistor matrix and manufacture thereof
US4684435A (en) * 1985-02-13 1987-08-04 Sharp Kabushiki Kaisha Method of manufacturing thin film transistor
US4958205A (en) * 1985-03-29 1990-09-18 Matsushita Electric Industrial Co., Ltd. Thin film transistor array and method of manufacturing the same
US4963955A (en) * 1985-04-11 1990-10-16 Canon Kabushiki Kaisha Photoelectric conversion apparatus
US4646424A (en) * 1985-08-02 1987-03-03 General Electric Company Deposition and hardening of titanium gate electrode material for use in inverted thin film field effect transistors
JPS62131578A (en) * 1985-12-03 1987-06-13 Seiko Instr & Electronics Ltd Manufacture of thin film transistor
US5188974A (en) * 1987-10-31 1993-02-23 Canon Kabushiki Kaisha Method of manufacturing semiconductor device
US5462887A (en) * 1993-11-22 1995-10-31 Ernst Luder Process for making a matrix of thin layer transistors with memory capacitors

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6133967A (en) * 1995-09-12 2000-10-17 Lg Electronics, Inc. Method of fabricating liquid crystal display with increased aperture ratio
US5942310A (en) * 1995-09-12 1999-08-24 Lg Electronics Inc. Liquid crystal display with increased aperture ratio
US6218206B1 (en) * 1998-03-31 2001-04-17 Mitsubishi Denki Kabushiki Kaisha Method for producing thin film transistor and thin film transistor using the same
US6140162A (en) * 1998-06-19 2000-10-31 Lg Electronics Inc. Reduction of masking and doping steps in a method of fabricating a liquid crystal display
US6232158B1 (en) * 1998-07-30 2001-05-15 Lg Philips Co., Lcd Thin film transistor and a fabricating method thereof
US6440784B2 (en) 1998-07-30 2002-08-27 Lg. Philips Lcd Co., Ltd. Thin film transistor and a fabricating method thereof
US6365469B2 (en) * 1998-08-26 2002-04-02 Agere Systems Guardian Corp. Method for forming dual-polysilicon structures using a built-in stop layer
US7978292B2 (en) 1998-12-31 2011-07-12 Samsung Electronics Co., Ltd. Thin film transistor array panels for a liquid crystal display and a method for manufacturing the same
US6287899B1 (en) * 1998-12-31 2001-09-11 Samsung Electronics Co., Ltd. Thin film transistor array panels for a liquid crystal display and a method for manufacturing the same
US20030133067A1 (en) * 1998-12-31 2003-07-17 Woon-Yong Park Thin film transistor array panel
US6806937B2 (en) 1998-12-31 2004-10-19 Samsung Electronics Co., Ltd. Thin film transistor array panel
US20020149710A1 (en) * 2001-04-13 2002-10-17 Keum-Nam Kim Flat panel display device and method of manufacturing the same
US20060011918A1 (en) * 2001-04-13 2006-01-19 Samsung Sdi Co., Ltd. Flat panel display device and method of manufacturing the same
US20060035397A1 (en) * 2001-04-13 2006-02-16 Samsung Sdi Co., Ltd. Flat panel display device and method of manufacturing the same
US7264981B2 (en) 2001-04-13 2007-09-04 Samsung Sdi Co., Ltd. Flat panel display device and method of manufacturing the same
US7319243B2 (en) 2001-04-13 2008-01-15 Samsung Sdi Co., Ltd. Flat panel display device and method of manufacturing the same
US6958252B2 (en) * 2001-04-13 2005-10-25 Samsung Sdi Co., Ltd. Flat panel display device and method of manufacturing the same

Also Published As

Publication number Publication date
US5648663A (en) 1997-07-15

Similar Documents

Publication Publication Date Title
US5686326A (en) Method of making thin film transistor
JP3973787B2 (en) Liquid crystal display device and manufacturing method thereof
US5828433A (en) Liquid crystal display device and a method of manufacturing the same
US5872021A (en) Method for manufacturing LCD device capable of avoiding short circuit between signal line and pixel electrode
EP0333151A2 (en) Thin film transistor
US4928161A (en) Thin-film transistor and wiring matrix device and its forming method
KR100231936B1 (en) Thin film transistor and manufacturing thereof
US5057889A (en) Electronic device including thin film transistor
KR100260359B1 (en) Lcd and method for manufacturing the same
EP1646076B1 (en) Manufacturing method of a thin film transistor array panel
US4816885A (en) Thin-film transistor matrix for liquid crystal display
KR100348995B1 (en) The method for fabricating liquid crystal display using four masks and the liquid crystal display thereof
EP0349255B1 (en) A thin-film transistor array
EP0810669A1 (en) Thin film transistor element array
JPH0756184A (en) Display device
JPH06167722A (en) Active matrix substrate and its production
US5523866A (en) Liquid-crystal display device having slits formed between terminals or along conductors to remove short circuits
KR0137938B1 (en) Thin film transistor & crossover structure for liquid crystal display and method of marking
KR100777850B1 (en) Array substrate and flat display device
CN1328621C (en) Circuit array substrate
JPS60251665A (en) Thin-film semiconductor device
JPS58192090A (en) Matrix array
JPH0568708B2 (en)
JPH0555573A (en) Thin film transistor and manufacture thereof
KR100247271B1 (en) A liquid crystal display having a storage capacitor and manufacturing method thereof

Legal Events

Date Code Title Description
CC Certificate of correction
FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
REIN Reinstatement after maintenance fee payment confirmed
FEPP Fee payment procedure

Free format text: PETITION RELATED TO MAINTENANCE FEES FILED (ORIGINAL EVENT CODE: PMFP); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FEPP Fee payment procedure

Free format text: PETITION RELATED TO MAINTENANCE FEES GRANTED (ORIGINAL EVENT CODE: PMFG); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FP Lapsed due to failure to pay maintenance fee

Effective date: 20051111

FPAY Fee payment

Year of fee payment: 8

SULP Surcharge for late payment
PRDP Patent reinstated due to the acceptance of a late maintenance fee

Effective date: 20060727

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 12